Objective: To explore the features, treatment outcomes and reasons for misdiagnosis in patients with multiple trauma, so as to decrease the incidence of misdiagnosis.Methods: A total of 3 163 patients with multiple trauma who were admitted in our department from August 1997 to August 2008, were retrospectively studied to compare the features of diagnosis and treatment. There were 2 117 males (66.93%) and 1 046 females (33.07%) with the mean age of 36.46 years (range, 14-80 years). Parameters such as general status, traumatic condition, diagnosis and treatment situation, prognosis and mortality were analyzed. The differences between misdiagnosis group and correct diagnosis group were compared in terms of severity of injury, complications and treatment outcomes to elucidate the cause and prevention of misdiagnosis.Results: The misdiagnosis rate of multiple trauma in this study was 16.19%. The major anatomic sites misdiagnosed were limbs and pelvis (299 positions, 39.50%), abdominal region and pelvic organ (148 positions, 19.55%),and thoracic region (109 positions, 14.40%). In misdiagnosis group, ISS, length of hospital stay, rates of disturbance of consciousness, critical cases and shock cases were 33.78± 19.64, (23.59±7.26) days, 49.22%, 33.01% and 47.46%,respectively, which were significantly higher than those of the correct diagnosis group (P＜0.01). And the data showed that the more serious the injury was, the higher the rate of misdiagnosis would be. The rate of primary diagnosis by trauma surgeons in correct diagnosis group was 75.78%, significantly higher than that of the misdiagnosis group ( x2=382.01,P＜0.01). The mortality rate of the mi sdiagnosis group was 2.93%, which was significantly higher than that for all patients ( x2=5.22, P＜0.05).Conclusions: The results indicated that patients with severe multiple trauma are at high risk of misdiagnosis in early treatment. The mortality rate of misdiagnosed patients is higher than the correctly-diagnosed patients. To prevent misdiagnosis, physicians need to take great care to conduct thorough clinical examinations and repeated evaluation.